451542: Method setDisplayText() of an IValueField is not null-proof 

Change-Id: Ie8b2290a833d40193b373c12048f061288e7764a
Task-Url: https://bugs.eclipse.org/bugs/show_bug.cgi?id=451542
Signed-off-by: Samuel Renold <sre@bsiag.com>
Reviewed-on: https://git.eclipse.org/r/36499
Tested-by: Hudson CI
Reviewed-by: Judith Gull <jgu@bsiag.com>
bug 451542: Method setDisplayText() of an IValueField is not null-proof 
https://bugs.eclipse.org/bugs/show_bug.cgi?id=451542
Change-Id: Ib8a061507234f3bd2ab343c5d6476cfa615d3aae
Signed-off-by: Judith Gull <jgu@bsiag.com>
Reviewed-on: https://git.eclipse.org/r/36549
Tested-by: Hudson CI